Wings of aircrafts that have a large span width facilitate high fuel efficiency. Possible issues arising with very large wing spans may be associated with the structure of the wings as they become very heavy in order to be able to carry the wing bending loads caused by maneuvers and gusts. To this end, some wings are divided in a first wing section and a second wing section that are rotatable to each other. Spring systems are arranged between the first wing section and the second wing section in order to hold the wing sections straight in normal operation, i.e. the flight position. The spring systems may exhibit non-linear behavior.
U.S. Pat. No. 7,275,722 B2 shows a wing tip device that comprises a foldable wing tip for reducing the load on the wing.
DE 10 2010 005 887 B4 discloses a wing having a foldable winglet. The different parts of the winglets are supported by a mechanical spring for reducing the load on the wing. The spring may be linear or non-linear.
EP 2 233 395 A shows a winglet having an autonomously actuated tab. To this end, a mechanism is provided for actuating the different parts of the wings.